Senior Full-Stack Engineer(s) - TypeScript / Node / React / Postgres - Cyber Intelligence Platform

Senior Full-Stack Engineer(s) - TypeScript / Node / React / Postgres - Cyber Intelligence Platform. I need one or more senior full-stack engineers to harden, secure, and monetize a working Cybersecurity Ecosystem Intelligence Platform - a typed knowledge graph in PostgreSQL (vendors, investors, executives, deals, threats, CVEs, conferences) with role-specific products on top: capital deal-intelligence, an equity-research terminal, persona dashboards, and a natural-language AI assistant. The product is largely built; I need help to harden it, close security gaps, and ship monetization. Tech stack: Node.js 24, TypeScript, Express 5, Drizzle ORM, PostgreSQL; React, Vite, TanStack Query, Tailwind, Radix/shadcn, force-directed graph viz; pnpm monorepo, contract-first OpenAPI to generated Zod + react-query hooks, node-cron ingestion pipeline, LLM-based extraction; OIDC + server sessions. Priorities: (1) Security - finish auth migration, remove legacy client-asserted owner ID, enforce server-side RBAC (IDOR risk); (2) Billing - Stripe subscriptions (Checkout + customer portal + webhook) driving plan state; (3) Scale hardening - chunk long-running importers, remove hardcoded query caps, graceful degradation for external API failures; (4) De-duplicate shared domain logic into a single library; (5) Unit-test the ranking/scoring logic. Deliverables: clean reviewed PRs against an existing well-structured monorepo, tests for new logic, no regressions to typecheck/test suites. To apply, include: 2-3 examples of TypeScript/Node + React projects you've shipped (ideally data-heavy or graph/analytics apps), a one-paragraph take on how you'd approach the auth/IDOR fix or the Stripe integration, and your availability and hourly/fixed rate. A full technical specification (PDF) is available to shortlisted candidates.